Method for culturing and cultivating fungi

ABSTRACT

In a method for culturing and cultivating fungi according to the present invention, the woods with the small diameter are used as the host woods. Into these woods with the small diameter, the fungi are inoculated through a cellulose sheet. The inoculated fungi are cultured and cultivated in a plastic bag having a porous site. 
     According to the culture and cultivation method of the present invention, the mushroom of high quality can be harvested in a very short period.

This application is a continuation of application Ser. No. 06/716,375,filed on Mar. 26, 1985, now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to an improved method for culturing andcultivating fungi.

Hitherto, the mushroom such as Lentinus edodes has been cultivated byinoculating mushroom fungi into a host wood with a diameter of 10 cm orabove and a length of about 100 cm, allowing to stand the inoculatedhost wood under suitable conditions until the hyphae grow and spread inthe host wood and growing or cultivating the mushroom. Such a host woodis available with difficulty due to the fact that the supply of the woodwith the diameter of more than 10 cm cannot be overtaken with itsexcessive demand. And, the wood with the diameter of less than 10 cm,especially less than 7 cm is unsuitable as the host wood since theregulation of the moisture, which is the very important factor in theculture of the fungi, is very difficult and always failed, thereby thefungi inoculated in the host wood cannot be cultured satisfactorily andsuccessfully because of the lack of moisture.

The use of sawdust instead of the host wood in the above method has beenproposed and practically effected on the industrial scale. As mentionedabove, the culture conditions, for example, the temperature, humidity,light and so on are required to be carefully regulated for culturing thefungi and this requirement is, of course, applied to in the culturemethod using the sawdust as the culture medium.

For easily and successfully regulating the culture conditions whoseregulation is very difficult and troublesome the use of a plastic baghaving a porous site has been proposed by the present inventor (JapanesePatent Publication No. 42287/82). That is, this method comprises

(a) introducing a culture medium which mainly consists of the sawdustinto the plastic bag having the porous site;

(b) sterilizing the bag;

(c) inoculating the fungi into the medium; and

(d) sealing the bag and culturing the fungi.

The characteristics of the above-mentioned culture method are to use theplastic film having the porous site which acts to prevent the culturemedium from contaminating with the unacceptable bacteria while supplyingair in an amount necessary and sufficient for the growing of the fungito the culture medium. Owing to the characteristics, the above-mentionedmethod has the following advantages and is highly evaluated:

(1) the conditions are successfully regulated during the culture of thefungi. In particular, the evaporation of the moisture is only a little;

(2) the suitable volume of air is supplied to the culture medium;

(3) the specific technics are unnecessary for the culture of the fungi;and

(4) the mushroom can be cultivated in very short period (some months),although at least some years are necessary until the harvest in theprior culture and cultivation method.

There are two important demerits derived from the use of the sawdust asthe culture medium in the abovementioned method, however, although ithas many advantages. One is that the grade in quality of the harvestedmushroom is lower as compared with that of the mushroom harvested byusing the host wood as the culture medium. The other is that the sawdustamount is not enough to meet its demand and accordingly to use thesawdust as the culture medium, it is necessary to take a special timeand cost for making the sawdust.

An object of the present invention is to dissolve the above-mentioneddemerits without impairing the advantages in the culture and cultivationmethod using the plastic bag having the porous site.

Another object of the present invention is to provide the culture andcultivation method using as the culture medium the wood with thediameter of less than 10 cm which had been thrown away as the worthlessuntil now.

Another object of the present invention is to provide the mushroom withhigh grade in quality.

These and other objects of the present invention will be apparent fromthe following descriptions.

SUMMARY OF THE INVENTION

The method for culturing and cultivating the fungi according to thepresent invention is characterized in that the host wood with a smalldiameter is used as the culture medium and that the fungi are inoculatedinto the host wood through a cellulose sheet.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is the view of the plastic bag used in the present invention.

FIG. 2 shows the state of introducing the host woods into the plasticbag of FIG. 1.

FIG. 3 shows the state of providing the cellulose sheet on the hostwoods.

FIG. 4 shows the state of culturing the fungi after their inoculationinto the host woods.

DETAILED DESCRIPTION OF THE INVENTION:

As shown in FIG. 1, the plastic bag (1) used in the present inventionhas the porous site (2). The plastic bag is made of a plastic having theheat durability so as to be capable of resisting high temperature duringthe following sterilization step and the strength so as to be capable ofresisting the impacts on introducing the host woods into the plasticbag. Generally, the film of polyolefin polyvinyl chloride, polyester,nylon and the like in the thickness of 30 to 150 microns is used.Preferably, the tubular film of polyolefin of the thickness of about 50to 100 microns is used owing to its low water vapor permeability and itsgood oxygen permeability. The plastic film in which any additive isincorporated may be used. Especially, the use of the translucent plasticfilm controls the light quantity, thereby the growing rate of the fungibeing increased. The plastic film is made into the plastic bag by anyconventional bag making machine such as a gusset-type bag makingmachine. The size and the form of the plastic bag are no particularlylimited and are freely determined.

The porous site (2) acts to prevent the passing-through of theunacceptable bacteria while supplying air suitably and has the heatdurability so as to be capable of resisting high temperature during thefollowing sterilization step. The porous site is not particularlylimited with respect to the material if the action and the naturementioned above are not impaired. Usually, a porous plastic film anon-woven fabric, a resin-treated paper, a compressed urethane foamsheet, a fiber cloth and the like are used. The microporous plastic filmhaving 0.1 to 1 micron in mean pore size is preferably used. The size ofthe porous site is determined by the volume of the host wood and isgenerally 0.5 to 100 cm² per 1 liter of the host wood volume. In a caseof the above-mentioned size being larger, the moisture is evaporatedfrom the host wood excessively and as the result the fungi do not growsatisfactorily. On the other hand, in a case of the above-mentioned sizebeing smaller, the air cannot be supplied sufficiently and as the resultthe growing of the fungi is not satisfactory, too. The preferable sizeof the porous site is 0.5 to 10 cm² /1 liter of the host wood volume.

The manner for providing the porous site on the plastic bag is notparticularly limited. For example a part of the plastic bag is cut offand then the porous plastic film in a size larger than the cut-off partof the plastic bag is adhered with any adhesive or through heat.

The culture medium in the present invention is wood (3) with thediameter of about 1 to 10 cm and the length of about 10 to 100 cm, thatis, a twig which is thought for those skilled in the art not to beavailable as the host wood and is left in the woodlands as it is.Various woods employed in the conventional culture and cultivationmethod as the host woods can be also employed in the present inventionUsually, Quercus serrata, Castanopsis cuspidata, Fagus crenata, Quercusdentata and the like are employed as the host wood.

In the present invention, at least one of the twigs mentioned above isintroduced into the plastic bag. Conveniently, a plurality of twigs areintroduced thereinto after bundling with, for example, a string or aband, as shown in FIG. 2.

Following the introduction of the host woods into the plastic bag, thecellulose sheet (4) is put on the host woods in the bag. However, it ispossible to put the cellulose sheet at the bottom of the plastic bagprior to the introduction of the host woods into the bag. And, it isalso possible to put the cellulose sheet on and under the host woods.This sheet is preferably put on the host woods, as shown in FIG. 3. Thiscellulose sheet may be a cardboard, a pasteboard, a pulp-molding sheetor a non-woven fiber cloth having the thickness of 0.5 to 5 mm, and thenutrients such as glucose cornstarch, malt extract and the like may beadded therein if necessary. Further, a bactericide, a mineral, anabsorbable high molecular material and the like may be present. If thesheet is put at the bottom of the bag, the risk of breaking the bag onthe introduction of the host woods will be reduced. For culturing thefungi more speedily, it is preferable to use the cellulose sheet inwhich water is absorbed adequately in advance.

Following the introduction of the cellulose sheet and the temporarysealing of the bag, the bag is subjected to the sterilization withsteam. On the sterilization, the cellulose sheet closely fits on thehost woods. In addition, the unacceptable bacterium are killed and thevital cells in the woods are also destroyed and therefore, the conditionof the host wood is very suitable and preferable for the culture of thefungi.

Then, the fungi are inoculated in the host woods through the cellulosesheet after cooling the bag to the temperature suitable for theinoculation of the fungi. The inoculation of the fungi through thecellulose sheet constitutes one of the characteristic features in thepresent invention.

The steps following the inoculation of the fungi are carried out in thesame manner as the conventional culture and cultivation method using thesawdust and the plastic bag. Firstly, the bag is sealed simply, forexample by a stapler and the fungi are cultured under a given conditionuntil the hyphae grow and spread through the host woods, as shown inFIG. 4. In this stage, the mouth of the bag may be cut and the mushroommay be cultivated in the same manner as the cultivation method using thehost woods with large diameter without the use of the plastic film.

The culture and cultivation method according to the mushroom fungi suchas Lentinus edodes., Pholiota nameko., Pleurotus ostreatus, Panellusostreatus, Pleurotus cornucopiae, Lyophyllum ulmarium., Flammulinavelutipes, Naematoloma sublateritium, Grifola frondosa., Grifolaumbellata, Coriolus versicolor., Coriolus hirsutus., Canoderma lucidum.,Hericium erinaceum, Auricularia auricula-judae., Tremella fuciformis.,and Tremella foliacea.

Even if the wood with the small diameter which easily evaporates themoisture is used as the host wood in the present invention, theexcessive evaporation of the moisture can be prevented by the use of theplastic bag having the porous site, thereby the fungi inoculated cangrow successfully and satisfactorily. In this way, the wood with thesmall diameter is available in the present invention. This fact is verysignificant since the woods with the small diameter used only as thefuel until now is found to be as the worth material. Further, incompared with the use of the sawdust, the use of the woods with thesmall diameter in the present invention gives many advantages. Forexample, the mushroom having the quality equal to that of the mushroomharvested by the conventional culture and cultivation method using thehost woods with the large diameter can be harvested. The woods leftalone in the woodlands can be used as the culture medium without anyspecial operation and step, while in the sawdust, the special step ofmaking the sawdust is necessary as mentioned above. In addition, thetime necessary for sterilizing the woods is very short (as compared withthe sawdust the sterilization time is reduced by about half). As clearfrom the above-mentioned, the use of the woods with the small diametercan provide not only the novel and epochal method for culturing andcultivating fungi, but also the economical fungi culture and cultivationmethod.

Moreover, the inoculation of the fungi through the cellulose sheet cangive many advantages, too. One is that the special technique forinoculating the fungi is unnecessary, while in the conventional culturemethod using the host woods, the so-called seed bullets are necessarilyimplanted in the host woods to inoculate the fungi and this implantationis the important and difficult work and the special technique is alsorequired thereto. Therefore, it is possible for the non-professional toculture and cultivate the fungi employing the culture and cultivationmethod according to the present invention. And, since the position ofthe woods in which the fungus is inoculated is not particularly limitedowing to the use of the cellulose sheet, the fungi can be inoculatedeverywhere in the host woods and the hyphae can grow and spread throughthe woods more speedily and quickly. As the result, the culture periodcan be shortened and it is possible to harvest the mushroom severaltimes in a year and improve the harvest of the mushroom.

Now the present invention is described with reference to the followingexample.

EXAMPLE

A tubular polypropylene film of 80 microns thickness and 65 cm lay-flatwidth was made into a bag of 35 cm width and 150 cm length by foldingeach 15 cm of both sides of the film and by heat-sealing the bottomusing a gusset-type bag making machine. Further, a microporouspolypropylene film (trade name: Juraguard #4510, a product of CelaneseChemical Co., in U.S.A.) site of about 28 cm² in effective area, whosemicropore is 0.2 micron in size and whose porosity is 45%, was providedon a somewhat higher position of the bag. The piled portion of thepolypropylene film bag with the microporous polypropylene film wasperforated in the form of a circle of 4 cm diameter, and the residualpiled portion was allowed to adhere by means of an impulse sealer.

The plastic bag so produced was allowed to stand in the form of columnof 35 cm width and 30 cm depth. A pulpmolding sheet of 35×30 cm wasplaced on the bottom of the plastic bag. On the other hand, 30 hostwoods with the 5 cm diameter and 60 cm length were bundled in the formof 5 rows×6 rows. The woods so bundled were introduced into the plasticbag and a cellulose sheet allowed to absorb water sufficiently was lacedon the woods. Then, the bag was sealed temporarily and sterilized at 95°C. for 3 hours with steam. After cooled, mushroom fungi were inoculatedon the cellulose sheet and cultured at about 20° C. for 2 months. As theresult, white hyphae were found throughout the total surface of the hostwoods

After the conclusion of the culture step, the host woods were taken outof the bag and placed at 10° to 20° C. for 1.5 month in the shade oftrees to cultivate mushroom.

As the result, about 3 kg of mushroom per a bag was harvested. Themushroom so obtained has the quality equal to that cultivated with thehost woods of the diameter of more than 10 cm.

What is claimed is:
 1. A method for culturing and cultivating fungi,comprising the steps of:(a) introducing at least one host wood piecehaving a diameter of 1 to 10 cm into a plastic bag having a porous sitetherein; (b) placing at least one cellulose sheet to promote inoculationof the fungi and to promote the culture and cultivation of the fungi,which contains nutrients and a bactericide, on said at least one hostwood piece in the bag; (c) sterilizing the bag; (d) inoculating thecellulose sheet with the fungi; and (e) sealing the bag and culturingthe fungi.
 2. The method according to claim 1, wherein the fungi arefungi of an edible mushroom or a medicinal mushroom.
 3. The methodaccording to claim 2, wherein the cellulose sheet is a cardboard, apasteboard, a pulpmolding sheet or a non-woven fiber cloth.
 4. Themethod according to claim 1, which further comprises placing a secondcellulose sheet underneath the host wood in order to prevent the risk ofbreaking the bag upon the introduction of the host wood into the bag. 5.The method according to claim 1, wherein said cellulose sheet has athickness of 0.5 to 5 mm.
 6. The method according to claim 1, whereinsaid fungi is a species selected from the group consisting of Lentinusedodes, Pholiota nameko, Pleurotus ostreatus, Panellus ostreatus,Pleurotus cornucopiae, Lyophyllum ulmarium, Flammulina velutipes,Maematoloma sublateritium, Grifola frondosa, Grifola umbellata, Coriolusversicolor, Coriolus hirsutus, Canoderma lucidum, Hericium erinaceum,Auricularia auriculajudae, Tremella fuciformis and Tremella foliacea. 7.The method according to claim 1, wherein the size of said porous site is0.5 to 100 cm² per liter of host wood volume.
 8. The method according toclaim 1, wherein the plastic material of said plastic bag is apolyolefin, polyvinyl chloride, a polyester, or nylon.
 9. The methodaccording to claim 1, wherein the thickness of the plastic bag rangesfrom 30 to 150 microns.